In online ads system, one common objective is to maximize the advertisers' value [1]}. Predicting click-through-rate (CTR) and conversion rate (CVR) are critical tasks for online advertising. For example, Edizel et al. [2]} proposed to use convolutional neural networks to predict ad-level CTR for sponsored searchPlease refer to §2.4 for more discussions., Lee et al. [3]} proposed a logistic regression model for conversion modeling, and pre-click and post-click user engagement are improved in  [4]},  [5]}, respectively.
